[geeks] New 2.5" SCSI HDs???

[Phil Brutsche]

Jonathan C. Patschke wrote:
> SAS (Serial Attached SCSI) and SATA (Serial ATA) are mostly the same
> protocol (same connectors, same command structure), but SATA has many
> features that are typically only "interesting" on servers and high-end
> workstations disabled.  As far as I know, you can use SAS devices on
> SATA buses (and vice-versa), but all of SATA's restrictions come along
> for the ride (ie: one device per channel, no LUN support, etc.)

You can use SATA everywhere you can use SAS, but not the other way
around - SAS drives won't work with SATA controllers.

As part of the SAS spec you can have a backplane with up to 8 drives in
it connected to an SAS controller port. They call these backplanes SAS
port multipliers or edge expanders.

Rancho's MiniSTOR 3R is an example of such a device.

Oh, and you can't use SATA and SAS in the same backplane. Different
controller ports are OK, but SAS and SATA on the same port via an
expander = no go, according to Dell & HP.

-- 

Phil Brutsche
phil at tux.obix.com